High-pressure sensors require a reliable sealing system to avoid leakage of liquid or gases which are subject to the high pressures to be measured.
Known systems form for example a conical sealing between a housing and a shaft of an inner part by means of a clamping force provided between these parts. FIG. 1 shows a schematic perspective view of a conical sealing according to the prior art. The arrow P denotes the respective pressure arising during a measurement. Within a housing 2 there is shown an inner part 3 engaging therewith and braced therewith by means of a thread which has an outwardly facing cone. This cone relies on a corresponding opposite cone at the housing 2 thereby forming a sealing portion 8. The high plastic deformation at this sealing portion, however, has been found to be disadvantageous. Furthermore, high wear at the sealing portion has been detected due to a displacement of these components relative to each other which arises because the cone of the inner part is markedly softer than the housing. Since the cone at the inner part 3 is clearly more elastic than the housing 2 a relative movement between the components mentioned may occur resulting in wear and eventually in leakiness of the sealing portion 8.
Another solution provides an intermediate part which is clamped between the housing and the inner part. FIG. 2 shows another sealing system according to the prior art. This system has an intermediate part 18 between an inner part 3 and a housing 2. This assembly, however, is not feasible for large diameters. Moreover, it lacks a self-amplifying effect.
O-Rings have the disadvantage of being not medium-compatible in the case of pressure media such as hydraulic oils or kerosene, corrosive gases or other pressurized materials.